Yamaha TRX850 Enthusiasts Forum

Hi Guys,
For those of you who have upgraded your brakes by switching to R1 calipers; did you also change the master cylinder.
The piston in the TRX master cylinder is 15.8mm in diamater and the R1 piston is only 14mm. I'm wondering if I need to change the master cylinder to an R1 or R6 item also???

I'm no expert but I believe you are advised to replace the master cylinder also or the brakes can feel a bit wooden ? I should imagine they will lack "bite" with the TRX cylinder.
Use the "search" option above and you will find all sorts of useful stuff on here mate. I know I have.

You don't have to change the mc but a lot of people do. Stopping power will be the same, but you will experience slightly more feel with the R1 mc.

trix wrote:Hi Guys,
For those of you who have upgraded your brakes by switching to R1 calipers; did you also change the master cylinder.
The piston in the TRX master cylinder is 15.8mm in diamater and the R1 piston is only 14mm. I'm wondering if I need to change the master cylinder to an R1 or R6 item also???

I would change the master cylinder, yes. There's a big difference in feel. The TRX m/c will feel quite wooden, which is to say, still a fair bit better than the original brakes!

Any pre-radial Thundercat, R1 or R6 should work (as I understand it). Buy a complete unit off e-bay, i.e. m/c, clamp and lever, as apparently "issues" can arise if you fit the wrong lever to the wrong m/c. Plus it's less hassle and you have a spare control set in case of a crash.

ive got pre radial R6 calipers on mine and i think they definatley feel 'wooden' i could'nt see what all the fuss was about swapping over from standard, in fact i'd say the standard brakes were probably as good but with more feel, i would change the master cylinder if you can get one cheap enough, they are made to work together

I only did the calipers first and the brakes were marginally better but there was very little feel at the lever, an R1 master cylinder sorted this.

Are you sure? The difference between stock calipers and blue spots is like night and day.

phuk72 wrote:Are you sure? The difference between stock calipers and blue spots is like night and day.

Agreed. Bled out properly?

Another advantage of fitting a whole system (calipers, m/c, and lever) is that it makes it easier to source aftermarket levers - if this tickles your fancy....just gotta source a clutch lever to suit to round off the transformation.....

I definitely bled it properly but what I found was I lost all the play at the lever so it was absolutely wooden, of course it could mean the master cylinder seals were shot but it was ok with the previous calipers. The R1 master cylinder is a different bore size to the TRX because it's matched to the R1 calipers.

The master cylinder lever fitment is the same so you can either fit the R1 5 position lever or the TRX 4 position one.

TimTrix wrote:
The master cylinder lever fitment is the same so you can either fit the R1 5 position lever or the TRX 4 position one.

it may fit but it doesn't make it right!

I've got a set of '03 R6 Blue-Spots on mine, but with a std TRX MC, and agreed there is power there but not much feel. But standing in the wings is a new R6 MC just waiting to be put on. I will probably do that when I get meself a set of Pazzo/ASV/TrackTech levers. Plus I need to get new discs as well

Bob

Found the brakes on my TRX to be wooden also (Japanese market model with Nissin MC and Brembo calipers). No 2nd hand blue spots were available here at the time (still aren't) so decided to upgrade the MC first, fitted a Nissin radial MC from an 05 GSXR 1000. This transformed the brakes and I am very happy with the feel and power so have decided to stick with the Brembos now
Got the MC from e bay in the USA but have had to curtail that sort of buying now that our "South Pacific Peso" is only worth 53c to the $US (was 77c when I got the MC a few months back

haggisbash wrote:Found the brakes on my TRX to be wooden also (Japanese market model with Nissin MC and Brembo calipers). No 2nd hand blue spots were available here at the time (still aren't) so decided to upgrade the MC first, fitted a Nissin radial MC from an 05 GSXR 1000. This transformed the brakes and I am very happy with the feel and power so have decided to stick with the Brembos now
Got the MC from e bay in the USA but have had to curtail that sort of buying now that our "South Pacific Peso" is only worth 53c to the $US (was 77c when I got the MC a few months back

Tell us North Atlantic peso grubbers all about it!

I have the FZR1000 six-pots with the FZR master cylinder. I quite like it really, far better grip then with the TRX calipers and a nice feel to them.